//黄金矿工
//测试链接：https://leetcode.cn/problems/path-with-maximum-gold/
public class GetMaximumGold {
    boolean[][] vis;
    int m, n;
    int[] dx = { 0, 0, -1, 1 };
    int[] dy = { 1, -1, 0, 0 };
    int ret;

    public int getMaximumGold(int[][] g) {
        m = g.length;
        n = g[0].length;
        vis = new boolean[m][n];
        for (int i = 0; i < m; i++)
            for (int j = 0; j < n; j++) {
                if (g[i][j] != 0) {
                    vis[i][j] = true;
                    dfs(g, i, j, g[i][j]);
                    vis[i][j] = false;
                }
            }
        return ret;
    }

    public void dfs(int[][] g, int i, int j, int path) {
        ret = Math.max(ret, path);
        for (int k = 0; k < 4; k++) {
            int x = i + dx[k], y = j + dy[k];
            if (x >= 0 && x < m && y >= 0 && y < n && !vis[x][y] && g[x][y] != 0) {
                vis[x][y] = true;
                dfs(g, x, y, path + g[x][y]);
                vis[x][y] = false;
            }
        }
    }
}
